/**
 * Copyright 2019-2029 geekidea(https://github.com/geekidea)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package io.geekidea.springbootplus.config.converter;

import org.apache.commons.lang3.StringUtils;

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

/**
 * <code>
 * <pre>
 * 日期转换器,将请求参数的日期字符串转换成java.util.Date类型
 * 日期格式顺序:
 * 	1.yyyy-MM-dd HH:mm:ss:S
 * 	2.yyyy-MM-dd HH:mm:ss
 * 	3.yyyy-MM-dd HH:mm
 * 	4.yyyy-MM-dd HH
 *	5.yyyy-MM-dd
 * </pre>
 * </code>
 * @author geekidea
 * @date 2018-11-08
 */
public class StringToDateUtil{
	/**
	 * 日期格式化数组
	 */
	private static DateFormat[] dateFormats = { 
			new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:S"),
			new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"), 
			new SimpleDateFormat("yyyy-MM-dd HH:mm"), 
			new SimpleDateFormat("yyyy-MM-dd HH"), 
			new SimpleDateFormat("yyyy-MM-dd"),
			new SimpleDateFormat("yyyy-MM")
			};

	/**
	 * <code>
	 * <pre>
	 * 1.如果日期字符串为空,则直接返回空
	 * 2.使用格式化组进行格式化,如果解析成功,则直接返回
	 * 4.否则,抛出非法参数异常
	 * @param source 请求的日期参数
	 * @return 解析后的日期类型:java.util.Date
	 * @exception IllegalArgumentException 非法参数异常
	 * </pre>
	 * </code>
	 */
	public static Date convert(String source) {
		if (StringUtils.isBlank(source)){
			return null;
		}
		source = source.trim();

		try{
			int timeLength = source.length();
			Long time = Long.parseLong(source);
			if (timeLength == 10){
				time = time * 1000;
			}
			Date date = new Date(time);
			return date;
		}catch (Exception e){

		}

		Date date = null;
		boolean flag = false;
		for (DateFormat dateFormat : dateFormats) {
			try {
				date = dateFormat.parse(source);
				flag = true;
				break;
			} catch (ParseException e) {
				// e.printStackTrace();
			}
		}

		if (flag) {
			return date;
		}else{
			throw new IllegalArgumentException("不能解析日期:" + source);
		}

	}
}
